Spray dried porcine plasma (SDPP) is a popular protein source which is added to weanling animal diets. Typically, it is fed at the highest concentration (4 to 10%) during phase I (early phase) of the weanling""s life. The SDPP concentration is then reduced as the animal advances in age and is eventually removed from the diet after three to four weeks post-weaning. Many studies have established that feeding SDPP to animals can significantly improve performance (growth rate, weight gain, feed efficiency, and lean mass or muscle yield) of those animals in comparison to increases seen with other protein sources used in the business. The greatest effects of SDPP are typically witnessed during the first week post-weaning and its influence is most pronounced when fed to pigs reared in challenging environments.
A newer method for improving performance of animals involves the administration to such animals of spray-dried hyperimmunized egg or milk. In the particular case of egg, the hyperimmunized egg is obtained from an avian which has been hyperimmunized with a vaccine comprising one or more specific immunogens. The hyperimmunization process causes the avian to undergo an immune response and antibodies to these immunogens are formed within the avian. These antibodies tend to accumulate in the hyperimmunized chickens"" eggs. As such, many in the art have begun feeding these antibody rich eggs to animals in order to treat certain diseases or disorders and thus render a better performing animal.
In one aspect, the invention is directed to a performance-enhancing feed supplement comprising a combination of plasma and an egg product, said egg product obtained from an avian hyperimmunized with one or more antigens.
In another aspect, the invention is directed to a method for enhancing performance of weanling pigs and calves comprising the administration to said weanling pigs and calves of an effective amount of a feed supplement comprising a combination of plasma and an egg product, said egg product obtained from an avian hyperimmunized with one or more antigens.
It is applicants"" discovery that when plasma is administered to an animal in combination with hyperimmunized egg, there is a synergistic increase in performance in that animal.
The plasma/egg product of the invention is a natural animal protein supplement composed of animal plasma, dried egg product, animal serum, serum albumin, and serum globulin. Plasma, serum, serum albumin and serum globulin are collected from USDA inspected bovine and porcine slaughter plants, preferably based within the United States. Eggs are collected from United States based flocks. Plasma proteins and eggs are dried separately. The individual components are then combined to make the final plasma/egg product.
Preparation of Hyperimmune Egg Product
The hyperimmune egg product can be produced by any egg-producing animal. It is preferred that the animal be a member of the class Aves or, in other words, an avian. Within the class Aves, domesticated fowl are preferred, but other members of this class, such as turkeys, ducks, and geese, are a suitable source of hyperimmune egg product.
The hyperimmune egg product is provided as a spray dried egg powder and is obtained from laying hens vaccinated with certain specific disease-causing pathogens. Example 1 discloses a preferred spectrum of pathogens especially effective for use in the present invention. The process of spray drying the pasteurized liquid egg minimizes damage to the antibodies in the egg, resulting in a product that has a high nutrient value and is capable of conferring passive protection to opportunistic enteric infections. Antibodies, as a group, are especially resistant to destruction by normal enzymes, and upon oral consumption, a significant fraction will pass through the gastrointestinal tract intact and active. Numerous studies report that orally consumed antibodies offer protection against specific enteric agents.
Having knowledge of the requirement for developing and maintaining a hyperimmune state, it is within the skill of the art to vary the amount of immunogen administered, depending on the egg-producing animal genera and strain employed, in order to maintain the animal in the hyperimmune state.
Alternative modes of hyperimmunizing egg producing animals can be used which, in place of immunogenic vaccines, include the use of genetic vaccines. In particular, any DNA construct (generally consisting of a promoter region and an immunogen encoding sequence) will trigger an immune response. Genetic vaccines consist of immunogen-coding vectors, fragments of naked DNA, plasmid DNA, DNA-RNA antigens, DNA-protein conjugates, DNA-liposome conjugates, DNA expression libraries, and viral and bacterial DNA delivered to produce an immune response. Methods of DNA delivery include particle bombardment, direct injection, viral vectors, liposomes and jet injection, among others. When applying these delivery methods, much smaller quantities may be necessary and generally result in more persistent immunogen production. When using such genetic processes, the preferred method for introducing DNA into avians is through intramuscular injection of the DNA into the breast muscle.
Plasma Collection
Plasma is a component of whole blood. In order to separate out the plasma, the whole blood is preferably treated with anticoagulant (i.e. Sodium Citrate) and then is pumped through a continual flow centrifuge to separate the plasma from the cellular components of blood. The resulting product is then preferably concentrated, for example through high-pressure membrane filtration, which also serves to remove most of the anticoagulant previously added. During processing it is preferred that the plasma is chilled to about 3xc2x0 C. Once concentrated, plasma is transferred to storage tanks that can maintain the temperature between 3-6xc2x0 C. In the preferred embodiment, the plasma is eventually spray dried, and packaged. Whole blood is preferably collected from USDA inspected bovine and porcine slaughter plants based in the United States. Plasma is a natural biological product that is harvested, not manufactured or fabricated.
Sprayed Dried Porcine Plasma
Spray dried porcine plasma (SDPP) has three major protein groups (fibrinogen, globulin and albumin). Studies were conducted with mice to determine the active fraction of plasma with respect to performance. During week one, mice fed purified globulins exhibited equal gains to mice fed SDPP and higher than mice fed fibrinogen or albumin. By week three, all mice fed fractionated plasma proteins had gains equal to mice fed SDPP which suggested that during the first week, the globulin fraction was responsible for the initial response in growth. The following examples show the effects of the plasma/egg product of the invention in terms of increasing performance of certain animals.